Installation of underground transmission pipe



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INSTALLATION OF UNDERGROUND TRANSMISSION PIPE Dec. 22, 1953 Filed Feb.5', 1952 IN VEN TORS Patented Dec. 22, 1953 IN STALLATON OF UNDERGROUNDTRANSMISSION PIPE Lawrence E. Thomas, Seattle, Wash., assigner ofthirty-three and one-third per cent to Clarence L. Ball and thirty-threeand one-third per cent to Robert L. Morgan, both of Seattle, Wash. Y

Application February 5, 1952, Serial No. 269,957

10 Claims. (Cl. 138-48) This invention relates to systems calling forunderground transmission of fluids and such, for example, as a steamheating system Where steam is piped underground from a central heatingplant and liquid products of condensation returned to the boiler. Y

There has been considerable eli-fort heretofore made toward developing asatisfactory method of installing underground transmission pipe, andpossibly the best of these prior'inethods is illustrated and describedin United States Patent No. 2,355,966, issued to David C. Goff August15, 194e. This particular method is one in which a trench, within whichthe pipes are to be laid, is provided along its floor With a beddingstrip of poured concrete. The pipes are spirally Wrapped with tape andsuspended Within the trench so as to be spaced above the bedding strip,and a body of concrete is then poured into the trench so as to encasethe Wrapped pipes. As a final step both the concrete bedding strip andthe surrnounting body or" concrete are waterroofed by mopping severalplies of asphaltic felt over the exposed top and sides. One objection toan installation made in accordance with the Goff teachings is that thesubstantially unitary casting extending monolithically for quiteextended distances, 20d and more feet, tends to develop cracks, and thesurface coating of asphaltic felt then becomes the sole protectionagainst penetration oi moisture. A further objection is the close inesting of the pipe by the poured concrete. A. yet additional objectionto the Goi system of installing underground piping is that weatherconditions are an important factor, and this is to say that pouring offresh concrete is necessarily prohibited either when the temperature isextremely high or at a'freezing point.

The present invention aims to provide a perfected system of installingunderground piping which will overcome each of the above objections. Theinvention consists in the new method of installing the underground pipeand in the product of said method. f l l In the accompanying drawing: Y

Figure l is a fragmentary perspective View portraying an installation ofunderground piping made in accordance with the preferred teachings orthe present invention.

Fig. 2 is a fragmentary vertical sectional view taken on line 2-2 ofFig.3 and f Fig. 3 is a transversevertical sectional view on line -cf Fig.2.

the use of pre-cast upper and lower nali-blocks. The lower said blocks,denoted by the numeral 5, serve as a base to support the pipe which isbeing laid, for example a steam-pipe t and a companion return-pipe l,and for the reception of such pipe there is provided in the top face ofthe haii-bloei; a respective groove, as ai and 9. These grooves extendlongitudinally oi the bloclrs, are somewhat Wider, say l, than thediameter of pipe for which they are intended, and in the preferredembodiment or the invenn tion each groove has a depth approximatingone-half of the Width. Designated by al, he upper said block functionsas 'a capping coinplement of the base-block and there is formed in theseupper or cap-blocks va registering counterpart of the grooves 8 and t,denoted this instance by it and il. The number and location of thegrooves will, ci course, be deter-V mined by the job for which theblocks are in tended, but it is recommended that there be at least a 4.waist section of concrete between adjacent grooves and that there be atleast a 6" iiank section oi Vconcrete isolating the grooves from theouter surface-s or" the block. 1

In making an installation, and assuming that there has been provided atrench i2 therefor, there is first provided a bed E3 on which to lay thelower or base-blocks ii. While a concrete pour might be employed toproduce the bed l prefer that the bed be constructed from line gravelcompacted between 2" X 4 side forms (not shown) and with enough coarsesand applied to the Surface to fill the voids. After being levelled androlled the bed is saturated with hot asphalt and in addition to thissaturating asphalt there is provided a ilood coat id oi hot asphalt.

The baseblocks are now laid end-to-end upon the bed While the flood coatis still hot, and as each successive block is laid there is trovvelledover its exposedend face, so as to extend out approximately 2 to 3beyond the grooves, a layer of refractory cement le and beyond thislayer of cement, to the bottom and side edge extremities of the block,there is applied a corresponding thickness oi rubber-base mastic it.While this cement and mastic are'in a Yplastic condition the next blockis pressed into place. l

When all the base blocks have beenset Ain place upon the bed, with theirmeeting faces bonded and sealed, asbestos cement slide pads l1 areplaced upon the iloor vor the grooves. These slide pads, which are ormay be about 6" long and a 1g thick, are placed at separated intervalsof, say 2.

The pipe iitters are now called in to set the pipe in place and whilenot illustrated in the drawing it will be understood that at spacedintervals along the length of the installation there are providedrelatively large pockets Within which looped sections of pipe may beaccommodated. These looped sections, joining straight sections of pipe,permit the latter to expand and contract with changing temperatures.

After the pipe has been tested and laid in the grooves the procedure isto duplicate, upon the upper faces of the base-blocks, the surf-'acetreatment given to the end faces, and this is to say that there is firstapplied a layer I8 of refractory cement over the waist strip and to theoutside of the grooves, and then laterally beyond the refractory cementthere isapplied a coating l-S-of rubberbase mastic approximatelycorresponding in thickness to the thickness ofv the refractory cement.

The operation is now in condition to receive the cap-blocks 4, placingthe sameY so as to stagger the joints relative to the joints of theVbaseblocks. Here again refractory cement and rubber-base mastic,designated in this instance by and 2|-, respectively, is used to bondthe blocks and seal the vertical joints.

The final steps in the process are to give all exposed surfaces a heavymop coating .22 Yof hot asphalt, whereupon a suitable. protectivemembrane 23 such as l5# asphalt felt. is applied, and this felt isitself covered with a iinish mopping of hot asphalt 24, both the asphaltmoppings and the felt paper being turned outwardly from the side edgelimits of the lblocks so as to bond with the flood coat of asphaltapplied to the bed and insure a completely water-proof jacket about theblocks.

The aggregate from which I ycast my blocks is or may comprise expandedmica (vermiculite), pearlite, cork, pumice, cinders,`sawdust,.diatomaceous earth or other like or suitable lightweightmaterial and used therewith is. air-entrained cement and a water-proongadmix, such for example as the chemical composition available. under thetrade-mark Oronite D-eO. After the cast blocks are thoroughly dry theyare additionally water-proofed by spraying the surface, and I preferablyuse for this purpose the product known to the trade as NS Clear Sealer.

The advantages of the invention willl it is thought, have been clearlyunderstood from the foregoing detailed description of the illustratedpreferred embodiment. Minor changes will suggest themselves and mayberesorted to without departing from the spirit oi the invention,wherefor it is my intention that no limitations be implied and that thehereto annexed claims be given a scope fully commensurate with thebroadest interpretation to which the employed language admits.

What I claim is:

1. An underground pipe installation comprising a level bed surfaced witha coating of asphalt, a concrete body resting upon said bed and composedof two courses of concrete blocksbonded together and having the jointsof the one course staggered relative to the joints of the other course,the meeting horizontal faces of said two courses of blocks being formedwith registering grooves acting in complement to produce alongitudinal-ly extending tunnel so spaced from all exposed surfaces ofthe double-coursed concrete body as to provide a major thickness ofsurrounding concrete on all sides of the tunnel, a fluid-carrying pipereceived in said tunnel, and a waterproofing jacket completely coveringthe top and sides of said concrete body.

2. The pipe installation of claim 1 in which the bond between the blocksis comprised in part of refractory cement and in part of rubber-base jmastic and with the mastic being toward the out- Lit) side of the.joints and separated from the grooves by the refractory cement.

3. The pipe installation of claim 1 in which the pipe rests upon cementasbestos slip plates placed at spaced-intervals throughout the length ofthey tunnel.

4. An underground pipe installation comprising a level. bed composed ofcompacted fine gravel and coarse sand saturated with asphalt, aconcrete'y body'resting upon said bed and composed of two courses ofpre-castconcrete blocks bonded together and having the joints oi the onecourse staggered relative to the joints of the other course, the meetinghorizontal faces of said two courses of blocks being formed withregistering grooves acting in complement to produce a longitudinallyextending tunnel so spaced from all exposed surfaces of thedouble-coursed concrete body as to provide a maior thickness ofsurrounding ooncrete on all sides of the tunnel, a fluid-carrying pipereceived in said tunnel, and a waterproofing jacket completely coveringthe top and sides of said concrete body.

5. An underground pipe installation comprising a level bed surfaced witha coating of asphalt, a concrete .body resting upon said bed andcomposed of two courses of concrete blocks bonded together and havingthe joints of the one course staggered relative to the joints of theother course, the meeting horizontal faces of said two courses of.blocks being formeelr with registering grooves actingin complement toproduce plural longitudinally extending tunnels and spaced one fromanother and from all exposed surfaces of the double-coursed` vconcrete,bodyas to provide a major thickness of surrounding concrete between andon all sides of the tunnels, duid-carrying pipes received in saidtunnels, andV a -waterproofing jacket completely covering the top andsides of said concrete body.

6. An underground pipe installation com-prising a level bed surfacedwith a flood coating of asphalt,A a concreteY body resting upon said bedand composed of two courses of concrete blocks bonded together4 andhaving the joints of the one course staggered relative to the joints ofthe other course, the meeting horizontal faces of said two courses ofblocks being formed with registering groovesacting in complementy toproduce a longitudinally extending tunnel so spaced from all exposedsurfaces of the double-coursed concrete body as to provide a'majorthickness of surrounding concrete on all sides Vof the tunnel, afluidcarrying pipe received in said tunnel, and a waterprooiing jacketcompletely covering the top and sides of said concrete body, said jacketcomprising a fairly heavy weight of felt paper applied between two mopcoats of asphalt.

7. An underground pipe installation comprising a level bed surfaced witha coating of asphalt, a concrete body resting uponvsaid bed andcomposedof twol courses of waterproofed concrete blocks with the joints of theone course staggered relative to thejoints of the other course andhaving contained in the jointsv both bonding cement and sealing mastic,the meeting horizontal faces of said two courses of blocks being formedwith registering grooves acting in complement to produce alongitudinally extending tunnel so spaced from al1 exposed surfaces ofthe double-coursed concrete body as to provide a major thickness ofsurrounding concrete on all sides of the tunnel, a fluid-carrying pipereceived in said tunnel, and a waterproofing jacket completely coveringthe top and sides of said concrete body.

8. An undergroundpipe installation comprising a level bed composed of negravel with coarse sand added to fill the surface voids and having thetop saturated with a ood coating of asphalt, a concrete body restingupon said bed and composed of two courses of waterproofed light-weightconcrete blocks with the joints of the one course staggered relative tothe joints of the other course and having both bonding cement andsealing mastic contained in all joints, the meeting horizontal faces ofsaid two courses of blocks being formed with registeringgrooves actingin complement to produce plural longitudinally extending transverselyspaced tunnels, cement asbestos slip plates placed along the floors ofsaid tunnels at spaced intervals of the length, a respectivefluid-carrying pipe resting upon said slip plates in each of thetunnels, and a waterproofing jacket completely covering the top andsides of said concrete body.

9. A method of installing fluid-carrying pipe, said method employinglight-weight waterproofed concrete blocks pre-cast in complementingpairs with the two blocks in each pair providing 1ongitudinallyextending surface grooves disposed in matching correspondence, themethod consisting in producing on compact earth and from fine gravel andcoarse cement a supporting level bed, giving said bed a flood coat ofhot asphalt and while such asphalt is still hot laying a lower course ofthe pre-cast blocks thereon with the grooved surface uppermost, thejoints between said blocks being cemented, laying the pipe which is tobe installed in the open grooves, laying and coincidently cementing anupper course of the pre-cast blocks upon the lower course so that thegrooves of the one course register with the grooves of the other andwith the joints staggered, and finally covering the top and sides of thedoublecoursed concrete body with a waterproong jacket by applying feltpaper between two mop coats of hot asphalt.

10. The method of claim 9 including the step of augmenting the jointcement, for purposes of sealing said joints, with rubber-base mastic andso applying the cement and sealer that the cec ment is at the inside andthe sealer is at the outside of the joints.

LAWRENCE E. THOMAS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,351,133 Scharwath Aug. 31, 1920 2,355,966 Goff Aug. 15, 1944

